Use AgentBay and $writing-plans in this isolated synthetic example. Read .agents/skills/agentbay-skill-installer/SKILL.md and the named provider’s installed SKILL.md and relevant resources before work. For a large skill file, read it in bounded consecutive sections so the instructions are not lost to output truncation. The exact provider source is supplied in source-map.json; this is selected-upstream verification, not a catalogue search. All listed sources were fetched at the recorded commit and Git blob checked. Verify the installed hash against the map. Read brief.md and constitution.md. The fixture fixes scope and waives further discovery questions; never claim a real user interview or human approval. Use only this named provider skill plus AgentBay; do not auto-invoke follow-on skills. Do not delegate, access accounts, install extra dependencies, edit installed skills or checks, run downloaded companion scripts, commit or deploy. Preserve each prior stage’s files.

Use writing-plans to turn the fixed spec, UX prototype and reviewed architecture into an implementation plan. Write specs/onboarding/plan.md, specs/onboarding/tasks.md and specs/onboarding/tasks.json only. Keep the plan under 900 words, with exact final files index.html, src/app.js and src/task.js, validateTitle(value) signature, state transitions, dependencies and fixed verification commands. The immutable tests define exact values/messages. Include spec coverage and Review Focus. Do not implement. tasks.json must be an array of objects with id (T001 etc), description, depends_on (ID array), parallel_with (ID array), satisfies (FR-ID array), files (path array), status="pending". tasks.md must list exactly those IDs/descriptions in the same order, with satisfies IDs. Cover every FR-001..008; preserve src/storage.js and all checks. Do not auto-invoke execution or other skills; stop after the three plan artifacts.